轻微损伤状态下架桥机主梁的非线性动力特性研究

项目名称： 轻微损伤状态下架桥机主梁的非线性动力特性研究

项目编号： No.11202062

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 王利英

作者单位： 河北工程大学

项目金额： 26万元

中文摘要： 本项目以现代数学和非线性动力学理论为基础对架桥机主梁在轻微损伤状态下的非线性动力特性进行研究。主要包括：把高阶谐波响应信号算法与结构强度方法相结合对架桥机主梁的损伤位置和程度进行研究，确定损伤阈值以及该方法的精度；用非线性动力特性做结构损伤检测研究时, 需要识别结构的刚度在损伤前后的变化，由于刚度与频率相关, 因此，本项目采用经验模态分析法研究结构频率随时间变化的特点；对主梁的非线性动力特性与损伤程度以及损伤位置之间关系做相应的实验研究,非线性动力特性通过时频分析和共振试验获得，把时频分析和共振试验两种方法结合在一起, 得到合适的时频分析所用窗口宽度, 获取振幅与频率关系曲线，通过分析振幅与频率的关系曲线族, 总结轻微损伤状态下主梁的非线性动力特性。通过以上研究验证非线性动力特性可以作为轻微损伤检测的指标，研究结果将具有重要的理论意义和工程实际应用价值。

中文关键词： 架桥机主梁；结构损伤；非线性动力学；安全因子集；

英文摘要： In this project, the nonlinear dynamic characteristics of the main girder of bridge girder erection machine under slight damages will be researched which are based on the modern mathematics and the nonlinear dynamics theories. The main contexts are as follows: the higher order harmonic response signals algorithm and the structural intensity method will be applied to studying the damage location and damage degree, determining the damage threshold and the precision of the methods. When the nonlinear dynamic characteristics are used to detect the structure damage, we need to identify the stiffness change of the structure before and after damage, because the stiffness is closely related to its frequency, the time-varying characteristics of structure frequency are studied by using the method of empirical mode. Subsequently, the relationships between the nonlinear dynamic characteristics and the damage position and damage degree will be tested with the experimental method, we will acquire the nonlinear dynamic characteristics from the time-frequency analysis and resonance test, then the time-frequency analysis and the resonance test are combined to obtain the window width in time-frequency analysis and the curve of the amplitude and frequency, after analyzing the family curves between the amplitude and frequency, the

英文关键词： The girder of Bridge Erection Machine；structural damage；nonlinear dynamic characteristics；security factor subset；